The invention relates to a data processing device, comprising a touch screen with a touch position sensor which comprises a first conductive panel and is suitable to detect a touch position on the screen from a change in a current pattern in the first panel. A data processing device of this kind is known from U.S. Pat. No. 4,853,498.
During use the position sensor for example applies the same electric voltage, to a plurality of locations on the first panel. When the panel is touched or approached by a finger or any other at least slightly conductive object, a capacitive effect is produced so that current is drained from the panel. The position sensor can deduce the position where the touch surface has been touched or approached by measuring the amount of current drained from the various locations on the panel whereto the voltage is applied.
Preferably, the touch force is determined simultaneously with the position. In that case, for example
the thickness of lines drawn by means of the position sensor can be adjusted in proportion to the force used, PA1 a distinction can be made between different types of use, such as control of cursor motions or icon selection, on the basis of different forces, PA1 a selection of a menu item can be confirmed by exerting additional force.